Transportable screening and proportioning machine



10, 1957 CARL-HERMANNHEXSE 3,

TRANSPORTABLE SCREENING AND PROPQRTIONING MACHINE Filed Sept. 9, 1963 2 Sheets-Sheet l CARL'HERMANN HEISE 3,297,159

Jan. 10, 1967 TRANSPORTABLE SCREENING AND PROPORTIONING MACHINE Filed Sept. 9, 1963 2 Sheets-Sheet 2 flvnwmp cA RL'HERMA N/V HEISE 'ggmm/ Afforneys United States Patent Ofiice 3,297,159 Patented Jan. 10, 1967 3,297,159 TRANSPORTABLE SCREENENG AND PROPORTIONING MACHINE Cari-Hermann Heise, 12 Kalandstrasse, Alfeld, Leine, Germany Filed Sept. 9, 1963, Ser. No. 307,629 Claims priority, application Germany, Apr. 26, 1963, H 48,970 3 Claims. (Cl. 209-319) The present invention relates to a screening and proportioning machine for bituminous road building materials and having a vibratory screen for sorting aggregates into different sizes, more particularly, to a screen arrangement which facilitates the interchangeability of individual screens of various size meshes in order to obtain different sizes of aggregates.

Bituminous road building materials generally contain aggregates of different sizes, with the sizes of the aggregates being selected so as to provide a surface having the required strength and load capacity. A completed bituminous roadway generally comprises at least two different size aggregates and may include four or six different sizes of aggregates depending upon the number of component layers of the roadway.

In the conventional machines, the dry road building materials are delivered by conveyor to a vibratory screen mounted in the mixing tower. The screen has different size mesh screens therein for sorting the aggregate into different sizes and delivering the sorted sizes of aggregate to corresponding hoppers. These hoppers then deliver predetermined quantities of their respective size aggregates to a mixer in which they are sprayed with bituminous material.

The vibratory screen assembly essentially comprises a steelhousing having a rectangular cross section with individual screens being vertically positioned therein in such a manner that the largest size aggregate is sorted first, and then progressively smaller sizes are sorted as the aggregate passes through the screen assembly. The entire screen assembly is mounted upon resilient supports and is driven by a centrally arranged shaft positioned transversely of the direction of flow of aggregate to the screen assembly so as to vibrate the entire assembly.

In order to sort a plurality of sizes of aggregates but at the same time to keep the overall length of the vibratory screen as short as possible, the individual screens are superimposed above each other. The smaller mesh screens are mounted in frames which are then secured in the housing of the screen assembly. The larger mesh screens can be directly secured onto the walls of the screen assembly.

Such screen assemblies have the disadvantage that individual screens are rigidly mounted therein in such a manner that replacement of these screens is very time consuming, particularly when it must be considered that the screens have often been heated to temperatures of about 200 C. by the hot bituminous mixtures. Thus, the replacement of screens because of wear or interchanging the screens for screens of different size mesh requires considerable time by skilled personnel.

It is therefore the principal object of the present invention to provide a novel and improved vibratory screen assembly for a screening and proportioning device, particularly adapted for road building materials.

It is a further object of the present invention to provide a screen assembly wherein the individual screens therein can be quickly interchanged with screens of different size mesh.

The objects of the present invention are achieved and the disadvantages of the prior art are avoided by the screen assembly of the present invention, wherein above each different size screen there is positioned a supplemental screen. Accordingly, the screen assembly of this invention has twice the usual number of different size screens. The screens are so arranged that the largest size aggregate which can be formed is determined by the size of the basic or permanent screens, Whereas smaller size aggregate can be produced. by inserting additional supplementary screens.

The supplemental screens comprise two longitudinally divided halves which are pivotally mounted on the inner surfaces of the longitudinal walls of the screen assembly housing. Each half is pivotable upwardly through an angle of about The adjacent longitudinal edges of the screen halves are provided with readily separable connections.

One half of each divided screen is mounted on an eccentric in such a manner that rotation of the eccentric 'will engage or disengage the connections on adjacent edges of the screen halves depending upon the direction of rotation of the eccentrics. The upper supplemental screen will always have a smaller aggregate size than that of the basic screen immediately beneath.

Other objects and advantages of the present invention will be apparent upon reference to the accompanying description when taken in conjunction with the several drawings, wherein:

FIGURE 1 is a side elevational view of the screening and proportioning machine of the present invention; and

FIGURE 2 is a transverse sectional view, shown somewhat diagrammatically, taken through the screen assembly of FIGURE 1.

A specific embodiment of this invention will next be described in detail with reference to the drawings, wherein like reference symbols indicate the same parts throughout the various views.

As may be seen in FIGURE 1, the transportable screening and proportioning machine comprises a frame 1 supported upon wheels 2 with the machine being supported in the operating position by stationary supports indicated at 3.

Mounted on the machine is a vibratory screen assembly 4 which comprises longitudinally extending walls 5 and 6 to define the housing of the screen assembly, with the housing having a substantially rectangular cross section. The screen assembly is driven by a motor 7 which is drivingly connnected to a transversely extending shaft 8 of the screen assembly.

Within the housing of the screen assembly there are superimposed a plurality of vertically positioned screens 4a through 40. These screens are of different size mesh with the largest size being on the top and the size becoming progressively smaller from top to bottom.

Positioned in the mixing machine below the screen assembly is a plurality of hoppers 9 with each hopper receiving a different size aggregate from the respective several individual screens in a manner well known in the art. From the hopper carefully measured quantities of different sizes of aggregate are discharged into a batch container 10 which is mounted on rails 11 for transporting the aggregate to the mixing machine.

The machine is also provided with a bucket conveyor 25 as shown in FIGURE 1 for delivering materials to the vibratory screen.

Above the screens 4a-4c there are positioned removable supplemental screens 12a1 2c.

As may be seen in FIGURE 2, the supplemental screen 12c is longitudinally divided into halves 13 and 14 with the outer edges of these halves being pivotally mounted on the axes 15 and 16 mounted on the inner surfaces of the walls 5 and 6 of the screen assembly housing. The

screen half 13 is mounted upon an eccentric 17, and the edge of the screen half 13 adjacent screen half 14 is provided with a hook 18 engageable with an eye or opening 19 in screen half 14 to form a readily separable connection between the screen halves 13 and 14. Screen 12b is similarly divided into screen halves 13a and 14a and a similar hook and eye connection 1 8a, 19a is provided therebetween which is under the control of eccentric 17a of the screen half 13a.

As may be seen in FIGURE 2, the supplemental screen 120 has its halves hooked together but not tensioned as is apparent from the position of the eccentric 17. In the same FIGURE 2, supplemental screen 12b is shown in its tensioned position with its eccentric being rotated downwardly.

Both supplemental screen halves are pivotable upwardly through an angle of about 90 into idle position as shown by the dotted lines at 20 for screen half 13.

Thus, merely by rotating the eccentrics, which can be done with a wrench or handle, the screen halves are disengaged from each other and then may be pivoted upwardly into idle position. The screen halves can be removed and interchanged with other screens of different size mesh in order to form difierent sizes of aggregate, if desired.

The eccentric means is also operable for tensioning the supplemental screen pertaining thereto so it will not sag when loaded.

' The screens 4a4c are basic or permanent screens and remain in the screen assembly. The supplemental screens above each of the basic screens are of a smaller mesh size than the basic screen immediately therebeneath. The basic screens have a mesh size for producing the largest possible desired size of aggregate. Therefore, to produce sizes of aggregate smaller than the largest possible size, it is only necessary to pivot the supplemental screens into operative working position. Since this operation can be carried out in only a few minutes by relatively unskilled personnel, the down-time of this screening and mixing machine is considerably reduced.

Thus it can be seen that the present invention provides a transportable screening and proportioning machine which can be quickly adjusted to give aggregates of various sizes depending on the requirements of the particular bituminous surface under construction.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions and, accordingly, it is desired to corn prehend such modifications within this invention as may fall within the scope of the appended claims.

What is claimed is:

1. A transportable screening and proportioning machine particularly adapted for road building materials, and comprising, a plurality of hoppers for containing aggregates of various sizes, a vibratory sorting screen assembly above said hoppers, said assembly having vertical longitudinal side walls and a plurality of vertically spaced screens extending laterally between said side walls operable for receiving mixed aggregate supplied to said screen assembly and for delivering various sizes of aggregates to the corresponding hoppers, a plurality of supplemental screens in said screen assembly located above respective ones of said spaced screens, and supplemental screens being of smaller mesh size than the respective ones of said spaced screens therebeneath, said supplemental screens being movable between screening and nonscreening positions, said supplmental screens being divided longitudinally into screen halves, pivot means pivotally connecting each screen half with a respective side wall of the screen assembly so that each screen half is swingable between an idle vertical position adjacent the respective side wall into a horizontal working position, and locking means on said screen halves for locking the screen halves of a respective supplemental screen together when in their said horizontal position.

2. A transportable screening and proportioning machine according to claim 1 in which said locking means comprises elements of separable connector means on the adjacent edges of said screen halves.

3. A transportable screening and proportioning machine according to claim 2 in which at least one of said pivot means for each pair of screen halves comprises eccentric means on the inner surface of the pertaining side wall of said screen assembly, and said locking means comprises hook means on one screen half of each supplemental screen and aperture means in the pertaining other screen half to receive said hook means whereby rotation of the respective eccentric means will permit engagement and disengagement of said hook means and aperture means and will furthermore tension the respective supplemental screen when the halves thereof are connected together.

References Cited by the Examiner UNITED STATES PATENTS 830,592 9/1906 Holdaway -422 1,587,196 6/1926 Soldan 209 405 2,077,615 3/1937 Chapman 209-319 X 2,298,352 10/1942 Downes 217x 2,344,228 3/1944 Barber 209 313 X 2,493,898 1/1950 Pollitz 259 154 2,727,733 12/1955 Carswell 239 154 2,893,602 7/1959 Barber 259-154 FOREIGN PATENTS 100,161 3/1898 Germany.

HARRY B. THORNTON, Primary Examiner.

- R. HALPER, Assistant Exan'iilzel'. 

1. A TRANSPORTABLE SCREENING AND PROPORTIONING MACHINE PARTICULARLY ADAPTED FOR ROAD BUILDING MATERIALS, AND COMPRISING, A PLURALITY OF HOPPERS FOR CONTAINING AGGREGATES OF VARIOUS SIZES, A VIBRATORY SORTING SCREEN ASSEMBLY ABOVE SAID HOPPERS, SAID ASSEMBLY HAVING VERTICAL LONGITUDINAL SIDE WALLS AND A PLURALITY OF VERTICALLY SPACED SCREENS EXTENDING LATERALLY BETWEENSAID SIDE WALLS OPERABLE FOR RECEIVING MIXED AGGREGATE SUPPLIED TO SAID SCREEN ASSEMBLY AND FOR DELIVERING VARIOUS SIZES OF AGGREGATES TO THE CORRESPONDING HOPPERS, A PLURALITY OF SUPPLEMENTAL SCREENS IN SAID SCREEN ASSEMBLY LOCATED ABOVE RESPECTIVE ONES OF SAID SPACED SCREENS, AND SUPPLEMENTAL SCREENS BEING OF SMALLER MEASH SIZE THAN THE RESPECTIVE ONES OF SAID SPACED SCREENS THEREBENEATH, SAID SUPPLEMENTAL SCREENS BEING MOVABLE BETWEEN SCREENING AND NONSCREENING POSITIONS, SAID SUPPLEMENTAL SCREENS BEING DIVIDED LONGITUDINALLY INTO SCREEN HALVES, PIVOT MEANS PIVOTALLY CONNECTING EACH SCREEN HALF WITH A RESPECTIVE SIDE WALL OF THE SCREEN ASSEMBLY SO THAT EACH SCREEN HALF IS SWINGABLE BETWEEN AN IDLE VERTICAL POSITION ADJACENT THE RESPETIVE SIDE WALL INTO A HORIZONTAL WORKING POSITION, AND LOCKING MEANS ON SAID SCREEN HALVES FOR LOCKING THE SCREEN HALVES OF A RESPECTIVE SUPPLEMENTAL SCREEN TOGETHER WHEN IN THEIR SAID HORIZONTAL POSITION. 